Apparatus for controlling electric motors.



H. E. BEY. APPARATUS FOR GONTROLLNG- ELEGTRIG MOTORS.

MPLMATIOH FILED AUG. a, 1908.

'UNITED STi/XTES PATENT OFFICE.

HARRY 1i). DEY. 0F JERSEY CITY, NEW JERSEY. ASSIGNOR TO BEN T. CABLE, OFNIHV YORK, N. Y.

APPARATUS FOR CONTROLLING ELECTRIC MOTORS.

Specification of Letters Patent.

Patented Dec. 1905).

Application tiled August 6. 1908. Serial No. 447,195.

To all 'ir/,font it 'may concern:

lie it known that l.'ll.\i:1ir ll. llizr, a citizen ot the l'nitedl*tate-1, and a resident otl Jersey tity. iii the county olI lludson andState ol' New Jersey7 have invented certain new and iiset'iillinproveineiits in A\pparatusl l'or tontinlling lllectric .i\lotors. otwhich the t'ollouiiig is a specitication.

).ly invention relates to that class otl apparatiisl iii which the speedol' the load is controlled by :i ditlieiential electrical eliectV on twomotors. ln such apparatus, a type oiLl which may be t'oiind iii mylatent No. Htlfnl. issued November 21st, 1905, to which iet't rence maybe had Jfoi' Isuch details as :ire not necessary to be. shown in thepresent application. a moving element of each inotoi' is inouiited upona .sha'l't common to both and tliei'eitore they turn in unison. Thisfact remains true whether powei is received through one motor or theother, or through both, and while I speak of them by the `generic terniof motor, it' will be readily understood that either of the socalledmotorsl may act as a dynamo, or generator, as the occasion a rises.llach ot these motors is essentially composed ot the iisiial elementsknown as aii armature and a tield. lVhile mechanically thc ditllereiitpartsI may be transposed ll will now assume that one tield magnet isarranged to remain stationaiy, the two ai'iiiatiires are mechanicallyjoined together and the other tield magnet is rotatively mounted todrive the load.

'lhe current which supplies the motors and which energif/ies the fieldmagnets is drawn, as iisiial` from main line wires and that portion ofit which cnergizes the. field magnet passes through resistances, orrheost ats` by means ot which the field strengths o'l the two motors arevaried relative to each other. As is well known the coiitiol of speedobtained by this arrangement is as follows: 'lhe speed of the twoelements which are joined together is fixed by the speed of thestationary field motor, and the speed of the latter in turn by its fieldstrength. Now the speed of the elements of second motor relative to eachother, is also fixed by the field strength of the second motor, and asits armature speed has been ixcd by thc speed of the other armature Withwhich it; is joined, the field of the second inc-tor will move at avelocity which will represent. the difference in speed of the twomotors. The direction Ordinarily one motor acts` as a motor and theother7 taking the reaction acts as ii dynamo.

When the two tield magnetsI are approximately o'l equal strength theload 4will reniain stationary but as the i'heostataiiii moves thusdecreasing the tield strength ol' one iield magnet by inserting moreresistance and increasing that ot' the other lield magnet by cutting outpart of the resistance one of the motors increases its speed owing towell known electrical reasons while the other decreases in speed and, asbeiore cx' plained the load has to make up the relative dii'leiience inspeed.

ll'hen controlling a load at a distance where it is not practicable toobserve the amount of motion oi load, tor example, the rudder of a shipcontrolled .tronithe bridge, it has been found desirable to inovetheindicator located aty the controlling stationtothe desired position otthe rudder. and have the rudder move to that position and automaticallystop. To accomplish this in thc simplest way I provide in addition tothe controlling rlieostat a second rheostat mechanically operated by the.load and connected in seriesl with the magnets and the controllingrlieol stat. as .shown in the accompanying diagram. As the secondrheostat is moved by the load it adds resistance to the low resistanceside and cuts out resistance tron'rthe high resistance circuits and thuswhen it arrives at the predetermined position the two circuits becomebalanced and the load comes to a standstill.

My invention consists therefore in an apparatiis for controllingelectric motors, 51

which is composed of a dynamo-electric inacliine with one stationary andone rotary element, a second dynamo-electric machine both elements ofwhich are rotary and one of which is mechanically connected to therotary element. of the iirst dynamo-electric machine, a primaryresistance whereby the relative strength of the iield magnets oi saidmachines is varied and controlled, and a count-er resistance operated bythe load.

In the accompanying drawing I have shown my apparatus onlydiagrammatically, as the details of construction of electric motors andtheir auxiliary devices are too well known to require description; the

important thing,` in practicing n'iy invention being to know thewiring:Y and the relative location ol the parts. i

A is the armature, of one olil the inotors which may be taken as theload motor.

E repreent` the load which in .this eaise iS a gear for turning therudder-Shaft, of a Vessel.

B is the armature of the stationary ielrl motor. on the shaft C.

F is the lieltl magnet Jfor armature lt is carried on the load shaft, l.

O is the stationary ielrl magnet for the arn'iature 'B which controlsthe shaft C.

" is the prin'iary resistance or rheostat,

'll' is the secondary or counter resistance or rheostat the arin ol'lwhich is turned by the worin l) on the loan-l shaft l to correspond withthe turning` of thev arin ot the primary rheostat.

The main line wiregl G, H.; supply onrrent to the armature A by thewir-ers J, K, which lead to the armature through collector rings and tothe lielil magnet by wires S? V, V, 35 through the resistanceb` 'l ainl'if'. They also supply the arniatnre B through the wires L, M, aiul it4stationary tiehl inagnoty (Y) by the wires S, lv", N and S through theresistanees 'll antl T.

The position of the handle a. of the rheostat or .resistance '.l`determines the speed anil direction ol the rotation imparted to the workshaft l from the niotor shaft (l.

rl`he operation of the device is aS follows: With the arni n, of thetransmitting` rheostat 'l at the central position as Shown in theilrawinLl there will he an equal. amount ol' resistance in nach lielrl.tlonsequently hoth Iiehls will he of equal magnetic, strength ani! theleiuleney ot hoth motors will he to rotate at the saine speed. Ris theSpeed of armature ll is fixed hy its stationany field anil thiI armatureis mechanic-ally connected with armature fr, armature A will have torotate at the saine Speed as armature antl thus there will he norevolution ofthe load E, which might otherwise he cansetlflojy thereaction between and itS field magnet l?.

If the arm a of rheostal; 'll is turned to the left; it cuts ontresiStanee from the ieldmagnet and at the saine time adds resistance tofield ,magnet F. This reduces the speed of armature B, and A, beingmechanically Both the arn'iaturezs are nionnteil,

connu-teil to it, is also brought (lown to the saine speed. The relativespeed between A* antl l? however has` heen increaeil. tjonge qaently theload E will take a motion opposite to that of armature frequal in speedto the iliil'erence between that of the two arini tures aiul therelative speerl of /i :intl lil. 'if howerer the arni L olf therheosala'lu 'l is turned to the riht7 the magnetic Strength ol themagnet if i increased while that o lfniagnet il in (leereasetl. lhnSSpeeding np the 'two armaturenl .i aiul l (lne to the ro ition. o toits; katationar)v magnet (l. [it the Sarno tiine lhe relative Speedbetween aiul lf" will be greatly reilueeil, yl'ho load then will rotattlin the saine liroeiion a; fr hnt at a, Speed equal to the lili'ercneohetweon the ratio o' ,L aiul l? and the spet-il of l ,4L-( la.- ingStationary.

Yr'lionewr the loal rotates it inovos; the arni fz ot rheostai' 'Y' in a`direi-,tion so relaietl lo the nuweinent of the arm (L as to terni tohring` they two ri nsliancef; hack to an equality7 h v culling' in anamount olf reSiSt ance equal to that ont oal o; enl'tingout an aniounteipial to that ent in. llrlhether 'the armal lollow each otaer opentupon whether one is relatively upside down or not as shown. An soon as;the iwe anc-@S have heen inatle inurl again, the loatl hemmenStationary. The worlr Shaft therefore is always ready to hold fast, inany given position which may he afannetl. by the primar;Y rh is* L.

"lhe many nnen, ant atlvantaffesa of this iii volition will, l think7 hereaihlj; inulernloofl without further explanation.

i claim:

An apparatus 'l'orcon torsl which eonef als olf a tlyn #nio chine withone slationatg/ and one rotary element, a Second'flynaino el yotricmachinea hol'h eleinent: oi which are rotar;7 intl one of which isnieelnn'rically tinnectecl to the rotaryr element oi the irst lJnainoelectric machine, a prinnirv resistance, whereby the relative .Latrongthof the {iol/l i'na5\iets oi? tial niarhine is Yariefl an@ controllori,and a counter resistance operated. with the lozul.

